The country’s largest wireless carriers have joined together for a national advertising campaign to discourage mobile users from texting while driving.

AT&T announced that competitors Verizon, Sprint and T-Mobile and more than 200 other organizations have joined its “It Can Wait” campaign. The effort will focus on the months between Memorial Day and Labor Day, which have been called the 100 deadliest days for teen drivers.

The campaign kicks off Monday, with the four wireless carriers bringing a multimillion-dollar, co-branded advertising blitz to raise awareness of the dangers of texting while driving. The companies are encouraging people to take a pledge against the practice at ItCanWait.com.

The campaign will focus on the stories of people who are living with the consequences of texting while driving.

Casey Neistat admits that the logistics of running a business isn’t his speciality. Instead, he shared with Denver Startup Week audiences how he went from high school dropout to an HBO show, a New York Times partnership and later, an app that got started while on a fellowship at the Massachusetts Institute of Technology.

Twitter is defending its decision not to remove a controversial tweet by President Donald Trump on Saturday that targeted North Korea, in a six-tweet response to critics who argued that Trump violated the platform’s rules.